The present invention relates to a kit comprising a paste A and a paste B, whereby(a) paste A contains(a1) at least one monomer for radical polymerisation; and(a2) at least one barbituric acid derivative as polymerisation initiator;(b) paste B contains(b1) at least one monomer for radical polymerisation;(b2) at least one heavy metal compound as polymerisation accelerator that is selected from the group consisting of heavy metal salts and heavy metal complexes;(b4) at least one alkali or alkaline earth halide; and(b5) at least one complexing agent for the alkali ions or alkaline earth ions (b4) that contains at least two ether groups; and whereby at least one of the pastes A and B contains, as component (a3) and/or (b3), at least one filling agent that is insoluble in (a1) and/or (b1), respectively.